1. Field of the Invention
The present invention relates generally to a method, apparatus, programs and storage medium for transferring data between different types of terminals for transferring call such as telephone, instant message, http and mail to an available terminal based on presence information, and more particularly to a method, apparatus, programs and storage medium for transferring data between different types of terminals for dynamically selecting the optimum terminal based on user's conditions and transferring call when a plurality of terminals are selected such as fixed phone, mobile phone and VoIP phone.
2. Description of the Related Arts
Recent years have witnessed rapid diversification of work style and communications infrastructure. For instance, office with no personal desk and telecommuting are among forms of office working style that are being practiced. Among communications terminals are extension phone, mobile phone, notebook PC, PDA and VoIP phone, with the nature of communications also diversified into call, instant message, http and mail. In such an environment facing diversified work styles and communications infrastructure, a single user can use a plurality of different communications terminals, and a service is being contemplated that would properly grasp in real time communications terminals available to the user using a presence system and, upon receipt of a request for call origination, select a specific communications terminal based on presence information and transfer the call. This call transfer service is not limited to extension phone when a call origination request is made from an external network to the user, and call may be transferred by selecting the user terminal on the external network based on presence information.
Means for managing presence information required for call transfer service include personal management system for managing, in a comprehensive and timely manner, a plurality of pieces of personal behavioral information such as personal information as to whether a person is at his desk, presence/absence information, schedule information, conference attendance information, discrimination for phone answering and building management based on personal information (see Japanese Patent Application Laid-Open Publication No. 1999-39570). On the other hand, to respond to value-added service demands—including high quality requested by end users only in specific voice communications such as business discussion and support service (specific call) and only in voice communications for reporting to police or fire department (emergency call), a technology is known that relates to a VoIP (Voice Over Internet Protocol) network system for transferring (including transmitting and exchanging) voice packets over IP (Internet Protocol) network and more particularly that relates to a VoIP network system for providing a value-added service by preferentially controlling calls associated with specific voice session (see Japanese Patent Application Laid-Open Publication No. 2003-324472). Further, a technology is known that establishes call to intranet and external network via DMZ (demilitarized zone) for establishing call between terminals connected to intranet and external network and implementing multimedia communications while at the same time ensuring intranet security (see Japanese Patent Application Laid-Open Publication No. 2003-324485). In such a call transfer service using conventional user presence information, however, while phone call can be transferred to where the receiver is at present by combining the receiver's whereabout information and the phone's transfer capability, this service does not specifically take into assumption that there are a plurality of terminals capable of receiving call. As a result of diversification of communications infrastructure, if a plurality of phones are available such as IP and ordinary phones where the receiver is now, there are demands to transfer call to the less expensive IP phone in the case of a call from the own company and to transfer call to the ordinary phone that, although being more expensive, offers better sound quality, rather than the IP phone with poor sound quality in the case of a customer call. However, the current call transfer service can only transfer call, even in the presence of a plurality of communications terminals available at the same location, to any one of the communications terminals that has been set in a fixed manner, making it impossible to properly respond to demands of users employing diversified communications terminals and preventing full use of the diversified communications infrastructure.